This invention relates to a mounting arrangement for an outboard motor, and more particularly to an improved elastic mounting for the components of an outboard motor.
As is well known, outboard motors are normally mounted on the transom of a watercraft for transmitting a propulsion force from the outboard motor to the watercraft. In conjunction with doing this, it is desirable to ensure in the mounting arrangement that the vibrations generated by the outboard motor in its operation are not transmitted to the hull of the watercraft. However, the propulsion forces should be transmitted. This prevents obvious difficulties.
Normally, the outboard motor is mounted resiliently by attaching a steering shaft to the drive shaft housing in a resilient manner. The steering shaft is then journaled in a swivel bracket, which is pivotally connected to a clamping bracket for tilt and trim movement. The resilient mounting for the steering shaft should isolate the vibrations of the powering internal combustion engine and the forces generated by vibration of the propeller from the hull but should be sufficiently rigid so as to transfer the driving thrust.
A wide variety of types of mounting arrangements have been employed, and these normally include an elastic bushing that has a connection to the drive shaft housing and to the steering shaft for providing the force transmission. However, due to the compact nature of the construction, it is not possible to provide the volume of elastic necessary to provide both the damping and the force transmission.
One reason for this is that a typical type of mount employs an annular elastic member that is cylindrical in shape and which has its outer periphery clamped to the outboard motor and its inner periphery affixed to the steering shaft. These outer and inner peripheries are both cylindrical in shape, and hence, the volume of elastic which can be utilized, and accordingly the stiffness, is somewhat limited, as will be described later.
It is, therefore, a principal object of this invention to provide an improved elastic mounting arrangement for an outboard motor that provides adequate elastic for damping and also provides good force transmission in a compact nature.
It is a further object of this invention to provide an improved mounting arrangement for the steering shaft of an outboard motor to the housing assembly of the outboard motor, achieving the aforenoted results.
In connection with the mounting of the elastic, if the elastic is itself directly engaged with the respective elements that mount it, then wear of the elastic can result. It is, therefore, a further object of this invention to provide an improved mounting arrangement for an elastic support for an outboard motor wherein the elastic is protected from wear.